Package com.mckoi.database

Class FilterTable

java.lang.Object
com.mckoi.database.Table
com.mckoi.database.FilterTable
All Implemented Interfaces:
TableDataSource
Direct Known Subclasses:
ReferenceTable, SubsetColumnTable
public class FilterTable extends Table
A table that is a filter for another table. By default, all Table methods are implemented to call the parent. This class should be used when we want to implement a Table filter of some kind. For example, a filter for specific columns, or even rows, etc.

NOTE: For efficiency reasons, this will store SelectableScheme objects generated by the parent like VirtualTable.

Author:
Tobias Downer

  • Field Details

    • parent

      protected Table parent
      The Table we are filtering the columns from.

  • Constructor Details

    • FilterTable

      public FilterTable(Table parent)
      The Constructor.

  • Method Details

    • getParent

      protected Table getParent()
      Returns the parent table.

    • getDatabase

      public Database getDatabase()
      Returns the parent Database object.
      Specified by:
      getDatabase in class Table

    • getColumnCount

      public int getColumnCount()
      Returns the number of columns in the table.
      Specified by:
      getColumnCount in class Table

    • getRowCount

      public int getRowCount()
      Returns the number of rows stored in the table.
      Specified by:
      getRowCount in interface TableDataSource
      Specified by:
      getRowCount in class Table

    • findFieldName

      public int findFieldName(Variable v)
      Given a fully qualified variable field name, ie. 'APP.CUSTOMER.CUSTOMERID' this will return the column number the field is at. Returns -1 if the field does not exist in the table.
      Specified by:
      findFieldName in class Table

    • getResolvedVariable

      public Variable getResolvedVariable(int column)
      Returns a fully qualified Variable object that represents the name of the column at the given index. For example, new Variable(new TableName("APP", "CUSTOMER"), "ID")
      Specified by:
      getResolvedVariable in class Table

    • getCellContents

      public TObject getCellContents(int column, int row)
      Returns an object that represents the information in the given cell in the table. This will generally be an expensive algorithm, so calls to it should be kept to a minimum. Note that the offset between two rows is not necessarily 1.
      Specified by:
      getCellContents in interface TableDataSource
      Specified by:
      getCellContents in class Table

    • rowEnumeration

      public RowEnumeration rowEnumeration()
      Returns an Enumeration of the rows in this table. The Enumeration is a fast way of retrieving consequtive rows in the table.
      Specified by:
      rowEnumeration in interface TableDataSource
      Specified by:
      rowEnumeration in class Table

    • getDataTableDef

      public DataTableDef getDataTableDef()
      Returns a DataTableDef object that defines the name of the table and the layout of the columns of the table. Note that for tables that are joined with other tables, the table name and schema for this object become mangled. For example, a table called 'PERSON' joined with a table called 'MUSIC' becomes a table called 'PERSON#MUSIC' in a null schema.
      Specified by:
      getDataTableDef in interface TableDataSource
      Specified by:
      getDataTableDef in class Table

    • lockRoot

      public void lockRoot(int lock_key)
      Locks the root table(s) of this table so that it is impossible to overwrite the underlying rows that may appear in this table. This is used when cells in the table need to be accessed 'outside' the lock. So we may have late access to cells in the table. 'lock_key' is a given key that will also unlock the root table(s). NOTE: This is nothing to do with the 'LockingMechanism' object.
      Specified by:
      lockRoot in class Table

    • unlockRoot

      public void unlockRoot(int lock_key)
      Unlocks the root tables so that the underlying rows may once again be used if they are not locked and have been removed. This should be called some time after the rows have been locked.
      Specified by:
      unlockRoot in class Table

    • hasRootsLocked

      public boolean hasRootsLocked()
      Returns true if the table has its row roots locked (via the lockRoot(int) method.
      Specified by:
      hasRootsLocked in class Table

    • printGraph

      public void printGraph(PrintStream out, int indent)
      Prints a graph of the table hierarchy to the stream.
      Overrides:
      printGraph in class Table